This invention relates generally to agricultural balers and, in particular, to such balers typically referred to as "round balers" which form cylindrical bales of crop material.
Two basic types of round balers exist today. The fixed chamber type of round baler forms bales with a soft core and a hard outer shell whereas the expanding chamber type of round baler forms bales with a hard core and a relatively uniform density throughout. An advantage of soft core bales is that they suffer only minimal rotting of the core even if moist crop material is baled. However, a disadvantage of soft core bales is that they tend to sag into an odd shape when stored for extended periods of time. An advantage of hard core bales is that they minimize the sagging problem of soft core bales but a disadvantage of hard core bales is that they have core rotting problems.
Three basic types of bale forming elements have been used in round balers. These are chain and slat aprons, belts and rollers. Each type of bale forming element has advantages and disadvantages. For example, an advantage of chain and slat aprons is that they are capable of starting bales in almost all crop conditions but a disadvantage of these aprons is that they often form bales with rough outer surfaces. An advantage of belts is that they form bales with smooth outer surfaces but belts have a disadvantage in that they have bale starting problems in certain crop conditions. Rollers also have the advantage of forming bales with smooth outer surfaces but they have a disadvantage of resulting in losses of crop material through the gaps between adjacent rollers.
It is an object of the present invention to provide a round baler which incorporates as many advantages as possible of the two basic types of round balers and the three basic types of bale forming elements while minimizing the disadvantages thereof.